diff --git a/src/backend/common/error.js b/src/backend/common/error.js
index bca39d18..c0894706 100644
--- a/src/backend/common/error.js
+++ b/src/backend/common/error.js
@@ -10,17 +10,9 @@ class ForbiddenError extends ClientError {
 class UnauthorizedError extends ClientError {
 }
 
-class CompileError extends ClientError {
-}
-
-class RuntimeError extends ClientError {
-}
-
 export {
   ClientError,
   NotFoundError,
   ForbiddenError,
   UnauthorizedError,
-  CompileError,
-  RuntimeError,
 };
diff --git a/src/backend/controllers/tracers.js b/src/backend/controllers/tracers.js
index 8ad303e7..ed5acecd 100644
--- a/src/backend/controllers/tracers.js
+++ b/src/backend/controllers/tracers.js
@@ -4,7 +4,6 @@ import uuid from 'uuid';
 import path from 'path';
 import { GitHubApi } from '/apis';
 import { execute } from '/common/util';
-import { CompileError, RuntimeError } from '/common/error';
 
 const router = express.Router();
 
diff --git a/src/backend/index.js b/src/backend/index.js
index b7ada4ce..394b7fb3 100644
--- a/src/backend/index.js
+++ b/src/backend/index.js
@@ -5,10 +5,8 @@ import bodyParser from 'body-parser';
 import * as controllers from '/controllers';
 import {
   ClientError,
-  CompileError,
   ForbiddenError,
   NotFoundError,
-  RuntimeError,
   UnauthorizedError,
 } from '/common/error';
 
@@ -24,8 +22,6 @@ app.use((err, req, res, next) => {
     [UnauthorizedError, 401],
     [ForbiddenError, 403],
     [NotFoundError, 404],
-    [CompileError, 422],
-    [RuntimeError, 422],
     [ClientError, 400],
     [Error, 500],
   ];